CVE-2017-13090

HIGH

Description

The retr.c:fd_read_body() function is called when processing OK responses. When the response is sent chunked in wget before 1.19.2, the chunk parser uses strtol() to read each chunk's length, but doesn't check that the chunk length is a non-negative number. The code then tries to read the chunk in pieces of 8192 bytes by using the MIN() macro, but ends up passing the negative chunk length to retr.c:fd_read(). As fd_read() takes an int argument, the high 32 bits of the chunk length are discarded, leaving fd_read() with a completely attacker controlled length argument. The attacker can corrupt malloc metadata after the allocated buffer.

References

http://git.savannah.gnu.org/cgit/wget.git/commit/?id=ba6b44f6745b14dce414761a8e4b35d31b176bba

http://www.debian.org/security/2017/dsa-4008

http://www.securityfocus.com/bid/101590

http://www.securitytracker.com/id/1039661

https://access.redhat.com/errata/RHSA-2017:3075

https://security.gentoo.org/glsa/201711-06

https://www.synology.com/support/security/Synology_SA_17_62_Wget

https://www.viestintavirasto.fi/en/cybersecurity/vulnerabilities/2017/haavoittuvuus-2017-037.html

Details

Source: MITRE

Published: 2017-10-27

Updated: 2017-12-30

Type: CWE-119

Risk Information

CVSS v2.0

Base Score: 9.3

Vector: AV:N/AC:M/Au:N/C:C/I:C/A:C

Impact Score: 10

Exploitability Score: 8.6

Severity: HIGH

CVSS v3.0

Base Score: 8.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Impact Score: 5.9

Exploitability Score: 2.8

Severity: HIGH